The central question is whether socioenvironmental factors in general and environmentally induced stress in particular are causally related to the occurrence and distribution of various types of psychiatric disorder and distress in communities. If so, what are the processes involved? Three main studies are underway to investigate these matters. All three draw on theoretical formulations and measurement procedures developed in our previous research and rely mainly on personal interviews for data collection. The three studies are: 1. A retrospective case-control study in New York City of 122 DSM-III major depressives, 65 persons with DSM-III schizophrenia and schizophrenia-like disorders ("schizophrenic disorders"), and 197 persons sampled from the general population and screened to constitute well controls. All are between the ages of 19 and 59. 2. A large scale epidemiological study of a probability sample consisting of about 5,000 men and women born in Israel between 1948 and 1962 and divided equally between Jews of European background and Jews of North African background; a subsample of 500 cases drawn from the 5,000 with diagnoses of schizophrenia, major depression, anti-social personality, substance abuse disorder, and a type of nonspecific distress that we are calling "demoralization;" 200 well controls; and about 2,800 first degree relatives of these cases and controls. 3. A prospective case-control study of 136 patients suffering from myofascial pain and 130 controls free of chronic pain. All are females between the ages of 18 and 64 have been followed at monthly intervals for a year. There are differences in some of the questions being asked in these studies and in some of the outcome variables being investigated. Each has at its core, however, a focus on five alternative theoretical models of how three elements of life stress processes--recent life events, personal dispositions, and on-going social situations--may contribute to adverse health changes.